The statements in this section merely provide background information related to the present disclosure. Accordingly, such statements are not intended to constitute an admission of prior art.
Known internal combustion engines may be configured to operate with compression-ignition (CI) combustion, and are often referred to as diesel or CI engines. CI engines employ fuel that may be derived from petroleum or vegetable oil and animal fat stocks. Fuel derived from petroleum includes long-chain hydrocarbon molecules and is referred herein as diesel fuel. Fuel derived from vegetable oil or animal fat stocks includes long-chain alkyl esters and is referred to herein as biodiesel fuel or biofuel. CI engines can operate on a 100% diesel fuel. Additionally, CI engines can be configured to operate partially or fully on a biodiesel fuel. A biodiesel blend ratio can be identified. By way of example, 0% BV fuel is identified as a 100% diesel fuel, and 100% BV fuel is identified as 100% biodiesel fuel. xx % BV fuel can be identified as a fuel composition including x % biodiesel fuel and (100%−x %) diesel fuel. For example, 40% BV fuel has a fuel composition including 40% biodiesel fuel and 60% diesel fuel. Diesel fuel and biodiesel fuel have different physical and chemical properties. Diesel fuel has a higher energy density than biodiesel fuel, whereas biodiesel fuel has higher oxygen content than diesel fuel. As a result, a greater mass of biodiesel fuel must be injected than of diesel fuel under the same circumstances in order to achieve similar combustion characteristics. Injected fuel mass for combustion can be adjusted in response to the biodiesel blend ratio. Further, when fuel is used for purposes other than combustion within the engine, injected fuel mass must be adjusted based upon the biodiesel blend ratio. CI engines generate particulate matter (PM), or soot during combustion. Exhaust aftertreatment systems of CI engines employ particulate filters to remove PM from the exhaust gas feedstream. Known particulate filters have a finite PM storage capacity and require regular purging including high temperature operation to avoid increased flow restriction in the exhaust system with corresponding reduced engine output power.